Uploaded November 2017 | Updated September 2026, 2 weeks ago
With this chemical heat pack, click the metal disk and watch the liquid crystallize. Younger students can safely feel the heat of a physical change. Advanced students can determine the heat of fusion of hydrated sodium acetate (fp = 54 C). Great for calorimetry experiments! Bending the metal disk initiates the crystallization of super-cooled sodium acetate and water; boiling the pouch in water returns the solid to a liquid. Can be used over and over.
With this chemical heat pack, click the metal disk and watch the liquid crystallize. Younger students can safely feel the heat of a physical change. Advanced students can determine the heat of fusion of hydrated sodium acetate (fp = 54 C). Great for calorimetry experiments! Bending the metal disk initiates the crystallization of super-cooled sodium acetate and water; boiling the pouch in water returns the solid to a liquid. Can be used over and over.
